Analysis Of The Suppression Of Microwave Breakdown By A Constant Magnetic Field Based On The Spectral Element Method

With the development of energy transmission technology,energy and field strength have become very large,high power microwave can improve the transmission efficiency of energy,but microwave breakdown will occur in the transmission process.The plasma generated in the breakdown process will absorb energy,resulting in microwave "tail erosion".In addition,plasma as a medium will reflect the incident field,causing damage to the device Therefore,it is of great significance to study the process of microwave breakdown.The work of this paper can be summarized in two aspects.On the one hand,based on the time-domain spectral element method platform,a time-domain numerical simulation and analysis platform for microwave breakdown is built.Through the time-domain simulation results,the change trend of electron density,microwave field strength,electron energy and electron temperature in the process of microwave breakdown can be clearly understood.The platform is coupled with Maxwell equations and electron fluid equations.The influence of pressure tensor term,convection diffusion term and Lorentz force term are considered.Then,the influence of environmental parameters on the microwave breakdown time is analyzed.The results show that the microwave breakdown time can be delayed by using inert gas,increasing pressure and reducing ambient temperature.On the other hand,it analyzes the suppression effect of constant magnetic field on microwave breakdown.On the time-domain numerical simulation analysis platform of microwave breakdown,considering the external constant magnetic field term,by analyzing the distribution of electron density on the same plane at different times,the simulation results show that the electron will drift under the action of Lorentz force of constant magnetic field,so as to reduce the electron density inside the device and achieve suppression.In addition,the influence of inhomogeneous plasma on the phase frequency characteristics of electromagnetic wave is analyzed.The simulation results show that the phase frequency curve decreases significantly near the maximum plasma frequency,while when the electromagnetic wave frequency is greater than the maximum plasma frequency,the phase frequency response curve gradually becomes linear.Under different magnetic field conditions,the phase frequency curve is only in the lower frequency range.In the high frequency range higher than the plasma frequency,the change is smaller.